The first function of Core B is to provide a systematic and reliable mechanism for the handling, storage, and distribution of tumor and blood specimens from patients and family members. A neuropathologist is available to immediately examine, divide, and distribute all tissue samples derived from the neurosurgical procedures performed on site. Tissue will be used for diagnosis, for short-term cell culture, frozen for molecular studies by the various projects, and stored for preparation of frozen sections. Information concerning diagnosis, origin, and distribution of the tissue will be recorded in a computer database to facilitate retrieval and tracking. These activities will be performed by neuropathologists and by the histotechnicians and research assistants under their direct supervision. A second function of Core B is to perform frozen or paraffin sectioning of the stored tissue for the various projects and to centralize the performance of any in situ labeling studies, such as immunohistochemistry, using the several markers described in the individual projects and in the Core. Data will be recorded and returned to the initiating project for analysis. This area will include examination of frozen sections for selection of appropriate tissue for use by the other projects in molecular studies. It will also include examination of stained sections for diagnosis of tumor samples for referred patients, selection and requesting of tissue blocks for subsequent study. The neuropathologists will supervise and perform these studies. A third function will be performance of RNA isolation and cDNA construction by the Core for distribution to other projects and for use in sequencing studies to support Project 6. These activities will be performed by research technicians jointly supervised by Drs. Bruner and Kyritsis. Our ability to centralize and monitor these vital Core functions, including collection, use, and distribution of primary brain tumor specimens and blood samples, provides an essential resource for coordination of the tissue and molecular studies of this Program Project.